Method and apparatus for yarn traverse



' Aug. 19, 1958 v F. HEBBERLING 2,343,173

METHOD AND APPARATUS FOR YARN TRAVERSE Filed Sept. 5, 1956 9Sheets-Sheet 1 INVENTOR FRIEDRICH HEBBERLING BY yam, 7'1 Gulf ATTORNEYAug. 19, 1958 F. HEBBERLING METHOD AND APPARATUS FOR YARN TRAVERSE 9Sheets-Sheet 2 Filed Sept 5, 1956 v 3 on 3 BY flaw-7 EQ QZ ATTORNEY Aug.19, 1958 F. HEBBERLING METHOD AND APPARATUS FOR YARN TRAVERSE 9Sheets-Sheet 4 Filed Sept. 5, 1956 I; IAID l w L 2 m m 2 2 ,z

m 3 J W x e mm a a o Q mm m 6 w g 9 2 2 1 2 Q A a 5? ll H l. I No 3 a mw o 6Q T a a a K a 23 mm W W- 2w n f g 8 k 2 M 0 N ATTORNEY Aug. 19,1958 F. HEBBERLING METHOD AND APPARATUS FOR YARN TRAVERSE 9 Sheets-Shes?5 Filed Sept. 5, 1956 INVENTOR FRIEDRICH HEBBERLING BY 3/ W9 6 Q, I

M47 ATTORNEY 1958 F. HEBBERLING 2,848,173

METHOD AND APPARATUS FOR YARN TRAVERSE Filed Sept. 5, 1956 9Sheets-Sheet 6 m INVENTOR I FRIEDRICH HEBBERLING '0 i WW M6041 ATTORNEYAug. 19, 1958 F. HEBBERLING METHOD AND APPARATUS FOR YARN TRAVERSE 9Sheets-Sheet 7 Filed Sept. 5, 1956 INVENTOR FRIEDRICH HEBBERLINGATTORNEY F. HEBBERLING METHOD AND APPARATUS FOR YARN TRAVERSE Aug. 19,1958 9 Sheets-Sheet 8 Filed Sept. 5, 1956 INVENTOR FRIEDRICH HEBBERLINGBY g mep j f Aug. 19, 1958 F. HEBBERLING mamon AND APPARATUS FOR YARNTRAVERSE I 9 Sheets-Sheet 9 Filed Sept. 5, 1956 PITCH RADIUS INVENTORFRIEDRICH HEBBERLING BY W 7 ATTORNEY Unite Stts METHGD AND APPARATUS FORYARN TRAVERSE Application September 5, 1956, Serial No. 608,158

10 Claims. (Cl. 24243) This invention relates to a method and apparatusfor the traverse of filamentary materials during windup, andparticularly to a method and apparatus for effecting the traverse of afilamentary material such as a textile yarn which is adapted to operateat very high processing speeds up to about 6000 yards per minute withthe obtainment of improved yarn packages or cakes, and also improved laydown.

The manufacture of synthetic textile yarns has been improved by advancesin technology to the point Where spinning and drawing speeds of theorder of about 6000 yards per minute are feasible; however, actualproduction is limited to considerably lower processing rates due to thefact that available yarn traverse methods and mechanisms are incapableof operation at these high speeds. Conventional yarn traversing duringwindup is incapable of producing satisfactory packages at high speedsbecause of inherent deviation from the ideal wind pattern. This idealwind pattern can be defined as one which, on traversal of yarn lay down,will lay a uniform amount of yarn at each increment across the width ofthe receiving package. Such a wind pattern may be visualized as a zigzagline wherein traverse reversals are accomplished in an infinitely shorttime. This is necessarily an idealized conception, because it isimpossible to effect an instantaneous reversal of traverse. Also, mostexisting apparatus which has been devised to reverse traverse at veryhigh speeds possesses the disadvantage that relatively high wear occursduring service. This has imposed a ceiling on efforts at speed-up ofmost traverses and actual mill processing speeds are today very muchless than 6000 yards per minute.

An object of this invention is to provide a traverse method andapparatus adapted to wind yarn or other filamentary material in highquality packages at supply speeds up to 6000 yards per minute, andabove. Other objects of this invention comprise the provision of atraverse method and apparatus which is adapted to wind yarn packagesonto cylindrical or tapered tubes, with either precision or random-woundoperation, at the option of the operator, while obtaining a minimum ofdegradation of the yarn product. Other objects of the invention includethe provision of a yarn traverse method and apparatus adapted to windzero-twist yarns, and to give packages having a high maximum wind angleup to about 36, all while reducing both wear and the noise encounteredin traverse drive. The manner in which these and other objects of thisinvention are obtained will become apparent from the detaileddescription and the following drawings, in which:

Fig. 1 is an exaggerated schematic representation in cross section ofthe sequence of yarn windup according to this invention,

Fig. 2 is a diagrammatic representation of the gen eral traverse windpattern of this invention,

Fig. 3 is a schematic representation of one embodiverse is obtained byutilization of a cam.

atent Fig. 4 is a sectional elevation through the differential geartrain of the apparatus depicted in Fig. 3, showing also the harmonicmotion generators, the output lever, the transmitting mechanism for thetraverse guide, and the traverse guide itself,

Fig. 5 is a side elevation view of'the yarn traverse guide arm andassociated elements looking in the di-- rection of 5-5, Fig. 4, a

Fig. 6 is a section taken on line 66 of Fig. 4,

Fig. 7 is a section taken on line 7-7 of Fig. 4; showing also theassociated programming cam and the cam follower connection,

Fig. 8 is a section on line 8-3 of Fig. 4 showing details of a frictiontrap auxiliary,

Fig. 9 is a sectional front elevation of a second embodiment of traverseapparatus according to this invention,

Fig. 10 is a section taken on line 10-10 of Fig. 9, with shaft 113 andits appurtenances, which lie behind shaft 104, omitted for clarity inrepresentation,

Fig. 11 is a side elevation view of a generator adapted to efiectprogramming of traverse for the embodiment of Figs. 9 and 10, V

Fig. 12 is a sectional view taken on line 1212 of Fig. 11, r

Fig. 13 is a half development of the pitch radius profile of the drivergear of the non-circular gear pair 124-425 of Figs. 9 and 10,

Fig. 14 is a half development of the pitch radius profile of the drivengear of the non-circular gear pair 124125 of Figs. 9 and 10, 7

Fig. 15 is a plan view of the slide assembly connecting the drive andtraverse mechanisms of the embodiment of Figs. 9 and 10, and

Fig. 16 is a side elevation of the slide assembly of Fig. 15 lookingtoward the drive mechanism.

Generally, the method and apparatus for yarn traverse according to thisinvention comprises a controlled sequence of winding which employs abasic harmonic motion at maximum amplitude of the traversing guide forthe lay down of yarn followed by successive stages ofamplitude-modulated winding, also in harmonic motion, by which thepackage is filled in and thereafter built up to the point where areverse basic lay down is again achieved, following which the entirecycle'is, in elfect, repeated as many times as required to obtain thedesired package diameter.

Reciprocation of the yarn traverse element in harmonic motion accordingto this invention has the important advantage that accelerations anddecelerations at the points of reversal of the traverse element areverymuch lower than with other motions. This advantage enables theemployment of exceedingly high average traverse velocities which permitthe windup of yarn at much higher speeds than is now possible. i

Referring to Figs. '1 and 2, a schematic representation of the method oflay down according to this invention is set forth in exaggerated showingto facilitate understanding of the interrelationship between yarn laydown and traverse wind pattern. As represented to greatly magnifiedscale, traverse with basic harmonic motion is accomplished with build upof yarn in the generally concave cross section depicted at A. Windup inthe basic step A occurs over about 11.5% of a single traverse halfcycle, as indicated in Fig. 2, which is a plot of traverse amplitudeversus time. The trace X of Fig. 2, is the true yarn lay and the areawithin the envelope can be considered the developed area within whichwinding is effected on the bobbin on which the package is built, itbeing understood that, for clarity in representation, only a very smallnumber of yarn traverses is shown Patented Aug. 19, 1958 3 for each:traverse step such as depicted in Fig. 2, as will behereinafterdescribed in detail.

It is apparent from Fig. l that the dished yarn buildup of the basicperiod A, if utilized by itself and without anything more, would beobjectionable because of resulting instability of the package, inabilityto unwind .properly, andalsobecause-rof' the peculiar form thereof,

:even. though very satisfactory traverse action is obtainable when thetraversing guide is driven with harmonic :motion. 'This inadequacy' iscured by employing a multiplicity of winding stages progressivelymodulated in amplitude to fill in the concavity and thereby give auniform diameter .packagethroughout. "The succeeding steps of thebuild-up therefore comprise filling in by lay down .of;a;.plurality ofother yarn increments, only eight of which (B to I) are shown by brokenline division in Figs. .lrand 2, although it will be understood that inpractice there are a great many more, so that all voids in the :packagearecompletely filled and uniform yarn -densityis obtained throughout.

The successive yarn layers depicted as B through I are ilaidsdown .asrepresented in Figs. 1 and 2 by. an amplitude-modulated harmonic motionwhich narrows the traverse progressively to the zero point indicated atY1of Fig.2, after which the reverse takes place with "progressivewidening of traverse as indicated from I through B. The final stepcomprises the reversely :oriented basic harmonic motion-denoted A;following which the entire cycle is, in effect, performed again for.as-ma-ny times as desired, depending on requirements. It will beparticularly understood that, with the progressive modulation indicatedby the smooth envelope of the curve of Fig. 2 there are no voids betweenthe ends 'of opposed layers such as appear in the simplified showing ofFig. l, and that a package of uniform density is obtainedinthe practiceof this invention. The entire cycle of winding from A through A depositsat most only about ,3 of yarn on the bobbin, and it willtherefore-beapparent that the showing of Fig. 1 is very greatlyexaggeratedin a radial sense to facilitate illustration of theprinciples involved. In this connection it should be mentioned that itis not necessary to commence yarn windup at the beginning of, or at anyother specific .pointin't-he cycle, due to the fact thatyarn lay downduringpindividual cycles is relatively so small that the retfectis of nopractical consequence.

As in conventional practice, the yarn input to the traverse mechanism isusually fairly constant speed-with- .in about -3%, at least, .butgreater variations than this ,canrbe tolerated without deleteriousresults to the packages obtained. The embodiment of this invention shownin Figs. 3-8 is not adapted for as high operating speeds as theembodiment of Figs. 9-16 hereinafter described .due tothe inertia loadspresent in the machine elements,

which cause objectionable vibrations at high speeds .unless great careis taken in the design to compensate for theseloads; however, theembodiment of Figs. 3-8 is capable of giving an improved yarn packageover those obtainable with conventional traverse mechanisms and is,therefore, a completely practical embodiment of my invention.

Referring to. Fig. 3,-which is a schematic representation of theembodiment of Figs. 48, it will be seen that the apparatus as a wholecan be considered as made up of which generator 11 is the other. Asindicated by the line representation 13, generator 12 is powered from--motor 10 and transmits its output through the drive connectionrepresented schematically at 29 to differential mechanism 17. Generator12 is at the same time connected through drive connection 20 to one ofthe three power connections of dilierential gear train 21. Programmingis achieved by direct connection of the programming cam-22, driven frommotor 10 through gear reducer 23, by connection, 24 with a second of thethree drive connections of difierentialgear train 21. The output fromdifferential '21 is introduced into generator ll'through driveconnection 28. Generator 11 may thus be considered the dependentgenerator of the pair comprising 12 and '11, and its output is deliveredthrough drive connection 16 to differential mechanism 17. Harmonicmotion generators 11 and '12 are independent of each other as regardsphase through the agency of the programming section acting on one of thegenerators only. The resultant output from 17 is delivered through driveconnection 32 which may, optionally, drive a 'displacement amplifier 33which, in turn, drives the traverse guide by direct connectiontherewith, indicated at 34.

The apparatus of Fig. 4 constitutes a complete design, inclusive of allof the individual elements of Fig. 3, details being elaborated on inFigs. 5-8. As shown in Fig. 4, the entire drive apparatus isconveniently mounted within a common housing 39 and is supplied withpower through .drive shaft 40, to which is keyed drive pulley 45. Theyarn bobbin is indicated at 42 and is disposed on spindle 43 journaledin bearings 44 and driven by pulley 41 connected to pulley 45 withtiming belt '46. Such adrive permits precision windup and is aconvenient arrangement from this standpoint.

Drive shaft 40 extends through housing 39 and is 'journaled thereon.

The independent harmonic motion generator 12 of Fig. 3, which .is theright-hand generator of Fig. 4, is

driven by direct connection with drive shaft 40, whereas generator 11,the left-hand generator of Fig. 4, is driven in part from generator 12and in part from programming cam 22 (not shown in Fig. 4) through thedifferential gear train indicated generally at 21 in Fig. 4.

Harmonic motion generators 11 and 12 are identical in construction andare detailed in Figs. 4 and 7. The generators consist of a circularplate journaled eccentrically on drive shaft 40, in the case ofgenerator 12, and eccentrically on hollow shaft 51, journaledconcentrically on shaft 40, in the case of generator 11. As shown mostclearly in Fig. 7, although also in the sectional showing of generator11 in Fig. 4, each plate element 50 is fixedly mounted within aconcentric ball bearing assembly 52, the outer race of which is snuglyfitted within yoke strap 53, sufficient clearance being provided betweenthe inside periphery of the yoke strap and bearing 52 to permit lateralmovement therebetween. The construction of the generators is thus thatof a Scotch yoke which is adapted to convert rotary motion into simpleharmonic motion through the agency of reciprocating rod 54 fixedlysecured to yoke strap 53. Rods 54 are guided in ways 55 provided inframe cross member 56. The output motions of generators 11 and 12 aretaken off by pinned connections at opposite ends of differentialmechanism 17 which, in this construction, is simply a centrallyfulcrumed lever. The lever of 17 is journaled on pin 57, which isattached at the ends to the two arms 61 (Fig. 7), making up one elementof the bell crank indicated generally at 62 pivotally supported onbracket 60. The other arm of hell crank 62 is joined by pin connectionwith transmitting link 63, which is in turn pinned at 71 to the end ofcrank 64 (refer Fig. 5), which drives the yarn traverse guide 66 throughan nular extension 65, pinned to shaft 70, which is journaled in bracket67 attached to the common base 68 of the apparatus. Yarn traverse guidearm 38 is pinned or otherwise fixedly attachedto shaft 70. If desired, asuitable displacement amplifier (33 of Fig. 3), such as a multiplyinglinkage or the like, may be interposed between link 63 and yarn traverseguide arm 38, the details of which are not further described hereinbecause of the conventional nature of the construction.

The details of construction of differential gear train 21 of Fig. 3 areshown most clearly in Figs. 4 and 6. The gear train is of theconventional type, including the gear pairs 7273 and 7475, and the cage76 integral with hollow shaft 51, which is provided with a shaft 78journaled at the ends in the two cage arms. Gear 81 is keyed to shaft 78and is driven by gear 82 keyed to shaft 83, which is hidden from view inFig. 4 due to its disposition behind shaft 78, but which is shown inFig. 6. Shaft 83, together with gear 82, is driven by gear 72 (Fig. 4),keyed to shaft 83 and in mesh with gear 73.

The programming section of Fig. 3 incorporates an amplitude modulationcam 87, shown in Fig. 7, which is driven by a gear reducer 23 (Fig. 3)at constant rotational speed, the reducer not being detailed hereinbecause of the conventional design. Cam 87 is keyed to the output shaft88 of reducer 23, the shaft being journaled on support stand 89 mountedon base 68. The cam profile is cut to obtain, in sequence, the yarnbuildup motions depicted through the range from A to I, and thence fromI to A (Figs. 1 and 2) in completion of the cycle, the two halves ofwhich are perfectly symmetrical about a vertical line drawn throughpoint Y of Fig. 2. The profile of the cam detailed in Fig. 7 wasdeveloped by laying out, from the reference line -0 as base, theindividual points in succession at the following angular spacings:

Interval Angle (in Radius (in degrees) inches) 44. 8 12. 00 57. 2 11. 8467. O 11. 48 74. 11. 12 80. 3 10. 72 84. 2 10. 44 87. 0 10. 28 88. 5 10.12 90 10. O0 91. 5 9. 88 93. 0 9. 72 95. 8 9. 56 99. 7 9. 28 105. 8 8.88 113. 0 8. 52 122. 8 8. 16 135. 2 8. O0 180 8. 00

The foregoing tabulation is descriptive of one-half of the cam, theother half being the mirror image of the determined half, and thusmerely a copy.

Programming motion is communicated from cam 87 to differential geartrain 21 via cam follower 90, pinned on one end of rocker arm 91, whichis journaled on pin 92 carried by support stand 93. The other end ofrocker arm 91 is provided with a sector gear element 94 which mesheswith driver gear 95 integral with hollow shaft 51 hereinbeforedescribed.

Referring to Figs. 4, 5 and 8, the yarn traverse guide arm per se isquite conventional in design, except that steps have been taken toreduce the mass of the parts as much as practicable while stillretaining high structural rigidity. This is accomplished by providing anarm 38 which is of generally channel-like cross section, as shown inFig. 8, and which is cut away circularly across the central web toreduce the mass. Yarn traverse guide 66 is conventional, having a slit96 for reception of the yarn, the guide being carried on the end ofoutwardly biased leaf spring support 97 attached at its other end to arm38, the clearance with respect to bobbin 42 of which can be adjusted byselective rotational disposition of eccentric cross-section bolt 98. Itis desirable to provide the traverse mechanism with a friction trapwhich permits consist of a strut 99 fixedly secured to shaft 70, the

upper curved end of which is slidably disposed between oppositely biasedspring ears 38a and 38b, welded or otherwise securely attached to theinside of arm 38. These ears permit relatively free movement of traverseguide arm 38 in the direction of the arrow of Fig. 8,

. while barring reverse movement.

in operation, it will be understood that drive shaft 40 drives generator12 by direct connection therewith and also drives gear 73, which iskeyed to shaft 40. The input to the differential gear train 21 is thusthrough gear 73 to gear 72, thence via shaft 83 to gear 82, which drivesgear and also shaft 78 keyed therewith. Gear 74 is keyed to shaft 78 anddrives gear 75, which is integral with plate 50 of generator 11. Thus,generator 11 is driven by differential gear train 21 as represented inFig. 3 by a line drive, such as that indicated by line 28 of Fig. 3,direct from generator 12.

The control effected by the programming section is imposed through gears94-95, hollow shaft 51, and cage 76 integral therewith, thence to theoutput of gear train 21, which is reflected in the output of generator11 and thus in the resultant with generator 12 taken out by the lever of17. generators 11 and 12 are actuated independently of each other asregards phase, due to the fact that generator 11 is responsive to cam 87whereas generator 12 is directly connected to drive shaft 40. Thereforethe resultant output at the center of pin 57 supporting the lever of 17is one-half of the sum of the instantaneous displacements of the rods54. The variation in phase between harmonic motion generators 11 and 12occurs progressively and cyclically and develops the traverse envelopedepicted in Fig. 2.

Programming with a cam 87 of the profile detailed develops an envelopein accordance with Fig. 2 included within the curves extending from P toY and R to Y which are symmetrical with respect to the longitudinal axisLL and which, referred to axis L--L', each have the followingtime-displacement relationship:

Cumulative Amplitude Time (Percent) (Percent) of the order of 6000yards/minute, or higher, without diificulties from inertial loads. Thesecond embodiment of the invention dispenses with linear harmonic motiongenerators, such as 11 and 12 and utilizes, instead, a beat generator,indicated generally at 100 in Figs. 9 and 10, which may be of the typeshown in Figs. 11 and 12. Beat generator 108 comprises a ring gear 101provided with a single planet gear 102, the output of'which is appliedto a conventional Scotch yoke mechanism through roller 103,eccentrically journaled a distance of about from the center of rotationof planet gear 102.

As hereinbefore described harmonic motion 7 Gear- 102 is drivenbyc'onstaiit speed shaft 104 through c'r'anlc 1U5. A g

The I Sootcli y'oke niechanism receiving" the output; from roller103isanfessential partof heat generator 100 and consistsof a slide 150provided with arena-r follower 153, the slide b'eing' reciprocablymounted in ways 151. The slide converts the rotary motion to oscillatorymotion, which-is transmitted to' y'a'rn' traverse guide arm 33 throughcrank ar'r'fi 154 provided at itsend with a slot receiving rollerfollower 153.

It can be established by kinematic analysis that, if the pitchdianieterof planet gear 102 is half of the pitch diameter of ring gear'ltll; andgear 101 is held stationary, then the travel of point- S, the center ofroller 103, will describe a'linear harmonic motion with respect to ahorizontalplane through S. Kinematic analysis further discloses that, ifthe pitch diameter of planet gear 102 is made a sn'iall peicentagelarger(e. g., about 1-l0%) than one-half the diameter of ring gear 101, theprojection of point S'on a horizontal plane will be a repetitive motionwhich yields a time-displacement curve with an e'nvelope'whichcorresponds to what, in physics, is denoted a common beat. Such anenvelope approaches the complete cycle envelope of Fig. 2 from thebeginning of period A through to the end of period A, but must becompensated for deviations therefrom, both in the basic period and inthe'remainder. This compensation is effected by the programming gearsystem hereinafter described, thus giving an'env'elope which is aduplicate of the pattern of Fig. 2.

It should be mentioned that proportioning the diameters of gears 101 and102 at a ratio of less than precisely 2 in effect causes a slow rotationof the plane along which linear harmonic motion is described and thusdevelops the beat hereinbefore mentioned. The envelope of the beat canbe compensated at will by control of the rotation of the plane in whichthe linear harmonic motion is described. This can be readily effected byprogrammed counterrot'ation of ring gear 101 a sufficient amount to,during the period in'time corresponding to A of Fig. 2, preserve aconstant amplitude harmonic motion and, during each subsequent discreteperiod, to yield amplitude modulation calculated to duplicate the otherperiods extending from B through I. Such counterrotation is impressed ongear 101 by integral connection of the gear with side gear 106'of thedifferential gear train denoted the mixer in Figs. 9 and 10. Theelements of the mixer gear train are mounted for free rotation on shaft104 which extends nearly the full length of housing 107.

The primary input for the mixer differential is supplied from side gearwhich is integral with spur gear 111, journaled on spider shaft 117 andin mesh with spur gear 112, which is journaled on reducer shaft 113 andpinned to non-circular gear hereinafter described.

The secondary input to the mixer differential is supplied through spidershaft 117 provided with stub shafts 118 and 118, upon which arejournaled spider gears 119 and 120, respectively. Spider shaft 117 issupported in freely rotatable relationship with respect to shaft 104 andis provided with non-circular gear 124 integral with spider shaft 117.Gear 124 is driven by non-circular gear 125 which is integral with theoutput side gear 127 of the differential denoted speed reducerdifferential in Fig. 9. Use of non-circular gears with the embodiment ofFigs.

9l6 is necessary to achieve variation in velocity as the it beingunderstood that the other half of each of' the gearsis the mirror imageof the half that is detailed.

Driver G ear125' Driven Gear 124 Pitch Radius (Inches) Angle YAie eIncrement (Dogs) Increment (Degs) The elements of the speed reducerdifferential are mounted-forffee rotation about reducer drive shaft 113and comprises spider gears 129 and'130 driven by spidershafts 131 and-1-31', respectively, integral with hollow shaft133l Spur gear 138,fixedly attached to side-gear 128 of the speed reducer difierential andjournaled on shaft 133, is driven by gear 144, Fig. 10, as gear 144 andthe follower 147 to which it is keyed are displaced by correction cam146, hereinafter described.

As shown in Fig. 9, power is introduced to the apparatus through maindrive shaft 135 provided with drive gear 136. Gear 136 is drilled tosupport the righthand end' of shaft 104 in freely rotatable relationshiptherewith. Driving power for shaft 104 is transmitted through theconventional gear train consisting of gear 136,- gear 139integral withgear 140, which is journaledon shaft 113; and two-part gear 141142 keyedto shaft 104. Shaft 113 is driven through gear 143 in mesh with gear142.

Practicable design of non-circular gears 124 and 12 5, particularly asregards feasible low pressure angles, neces sitates the independentintroduction of a cyclic speed component to the non-circular gear pairwhich is adapted toanticipate a portion of the speedchangessynchrono'usly encountered during the rotation of thenon-circular gears. This is accomplishedby use of a correction cam 146and follower 147 combination, as shown in Fig. 10,

which reciprocates arm 132 andthereby introduces the anticipatorycomponent into the'spe'ed reducer diiferen tial. Cam 146 is=circular inprofile but disposed at an eccentricity ofabout /fi" with respect to'theaxis of shaft" 148 to'which 146-is attached. Shaft 148 is drivenby gear149, keyed thereto, which is inmesh with side gear 111, the arrangementbeing such that the anticipatory component pickup issubordinated to gear112. also in mesh with gear 111, and therefore non-interferingtherewith. H

F0llowe'r14'7 has keyed thereto gears 144 and 145, betweenwhichis'journaled the lower end of reciprocatory arm 132. Th'e'u'pperend o'f arm 132 is journaled on shaft 113 and oscillation of arm 132occurs about the axis of shaft 113 as center. Arm 132 together withfollower 147 and gears 144 and move in concert and transmit theanticipatory velocity component to noncircu'l'ar gear 125 through gear144 in mesh with gear 138 via the speed reducer differential. It will beunderstood, of course, that a constant speed input is simultaneously andcontinuously supplied to themixer from gear 112, pinned to gear 125,which is introduced as one input to the mixer difierential, the otherinput of which derives from the non-circular gear 124. The output of themixer differential drives ring gear 101 and duplicates the envelope ofFig. 2, through the Scotch yoke output mechanism, by controlledcounterrotation of gear 101 with respect to planet gear 102.

The apparatus shown in Figs. 9-16 is provided with a power takeofl forprecision winding consisting of drive gear 163, which is keyed to shaft104 and meshes with gear 164 keyed to bobbin shaft 165, some of theelements of the cooperating gear train making connection with bobbinspindle 116 being omitted for simplicity of representation in Fig. 9.The bobbin 167 is mounted on spindle 166 in conventional manner, and isnot further described herein because it is not related to thisinvention.

From the foregoing, it will be understood that this invention provides amethod and apparatus for winding yarn on a package which employs a basicsimple harmonic motion upon which is superposed a progressivelydecreasing amplitude modulated fill-in traverse motion, following whichthe exact pattern is repeated, but in reverse order to complete thecycle. In practice, it appears that up to approximately 1% deviation interms of radial yarn lay down from that obtainable with true harmonicmotion can be tolerated, and this is also true for about the samepercentage departure from shape as regards the modulation envelope.Thus, control of the wind pattern according to this invention is quitecritical.

It will be understood that each of the cycles occurs within a very shortperiod of time and, even with high yarn supply speeds, the thickness ofyarn lay down during any one cycle is very small and is actually of theorder of M The advantages inherent in utilizing harmonic motion as thebasis of windup is that gradual deceleration is a natural accompanimentof the mode in approaching points of reversal, making it possible towind yarns at very high average speeds Without encountering inertialloads so great as to impose unsupportable stresses on the apparatuscomponent while, at the same time, not demanding excessive power foroperation.

The cam-controlled embodiment of Figs. 4-8, and the positivelygear-driven embodiment of Figs. 9-16, represent two basic types ofapparatus which can be utilized to achieve windup according to theinvention; however, it will be understood that a great number of devicesand modifications are adapted to achieve the inventions objectiveswithout departure from the essential spirit, wherefor it is intended tobe limited only by the scope of the following claims.

What is claimed is:

1. A method for yarn traverse in the winding of a length of yarnconsisting in sequence and cyclically of winding said yarn in a firststage with a traverse action in harmonic motion at maximum amplitude,then winding said yarn with a traverse action in harmonic motion ofprogressively modulated amplitude during which the package is filled inand thereafter given a yarn lay down reversed in sense to the yarnconfiguration built up during the interval when said package is filledin, and then completing the cycle by winding said yarn with harmonicmotion at maximum amplitude in reverse order to said first stage but forapproximately the same time duration.

2. A method for yarn traverse in the winding of a length of yarnconsisting of building a substantially constant diameter yarn cake bysequentially and cyclically winding yarn in a symmetric pattern over thefull cake length with a traverse action in harmonic motion at maximumamplitude, continuing said winding with harmonic motion modulated inamplitude so as to fill in the concavity created during said windingover the full cake length, thereafter winding with a harmonic motionreversely modulated in amplitude to said harmonic motion modulated inamplitude so as to fill in said concavity, and then completing the cycleby winding said yarn over the tion at maximum amplitude forapproximately 11.5%

of the duration of a half cycle, then winding-said yarn with a traverseaction in harmonic motion of progressively modulated amplitude so thatthe following percentage amplitudes correspond approximately to thefollowing percentages of the period of said half cycle:

Cumulative Percentage Percenta e of Amplitude Period of all Cycle andthen completing the cycle by repetition of the complete half cycle butin the reverse order to that first detailed. I

4. A method for yarn traverse in the winding of a length of yarnconsisting in sequence and cyclically of winding said yarn with atraverse action in harmonic motion at maximum amplitude forapproximately 6.75% of the duration of the cycle, then winding said yarnwith a traverse action in harmonic motion of progressively modulatedamplitude from said maximum amplitude to zero so that the followingpercentage amplitudes correspond approximately to the followingpercentages of the period of said cycle:

thereafter winding said yarn with a traverse action in harmonic motionof progressively modulated amplitude from zero to said maximum amplitudebut in the reverse order to the first-mentioned winding at modulatedamplitude so that the following percentage amplitudes correspondapproximately to the following percentages of the period of said cycle:

and then completing said cycle by winding said yarn with a traverseaction at maximum amplitude for the final 6.75 of the duration of saidcycle.

5. An apparatus for yarn traverse in the winding of a length of yarncomprising in combination a yarn traverse guide arm provided with a yarntraverse guide, drive means for said yarn traverse guide arm developinga harmonic motion output, programming means cyclically and sequentiallycontrolling said harmonic motion output of said drive means from maximumamplitude through progressively decreasing amplitude to zero and then inthe reverse sense from Zero through progressively increasing amplitudeto maximum amplitude, and a drive connection between said drive meansand said yarn traverse guide arm.

V 6. Ali spear-ears for yarn traverse in the winding of a lrigtli ofyear acesraia jib claim wherein saidprogramming means 'ycliciaill'y andsequentially controlling said harmonic motion outputcause's said drivemeans to area said yarn traverse guide arm at substantially thefollowingpercentage amplitudes in harmonic motion at the followingpercentages of the period of the yarn windiiig' cycle:

v Cumulative ar n s 9 P r enta Amplitu' e of Period of Winding Cycle 1000' 'lQOj 6. 75 97 l0. 0 87 20. 0 7.4 :0 51 4D. 0 ,0 50. 0 51 60.0 74:70.0 87 80.0 97 90. 0 100 93:25 100 100 ,p I Cumulative PercentagePercentage Amplitude of Period of Windin Cycle 100 0 100 6:75 97 10.0 8720. 0' 74- 30. 0 51 40.0 v0 50.0 51 68.0 74 70.0 87 80.0 97 90. 0 mo93.25 100 100 12 and a drive connection between said output element ofsaid differential mechanism and said yarn traverse guide arm.

8. An apparatus for yarn traverse in the winding of a length of yarnaccording to claim 7 wherein said programming means is a unidirectionalrotating cam.

9. An apparatus for yarn traverse in the winding of a length of yarncomprisi-ngin combination a yarn traverse guide arm provided with a yarntraverse guide, drive means for said yarn traverse guide arm consistingof a beat generator, programming means progressively and cyclicallycontrolling the output of said beat generator to circumscribe harmonicmotion referred to the longitudinal axis of the output pattern of saidbeat generator to give the following percentage amplitudes of saidharmonic motion at the following percentages or the period of thewinding cycle:

and a drive connection between said heat generator and saidyarn traverseguide ar'm. l 10. An apparatus for yarn traverse in the winding of I alength of yarn according to claims wherein said programming meanscomprises a gear difierent'ial wherein a constant speed input iscombined with a variable speed input to give an outputprog'ress'ivelyand cyclically controlling the output of said heat generator.

References Cited in the file of this patent UNITED STATES PATENTS285,438 Jones June 9 1942 FOREIGN PATENTS 532,861 Germany Sept. 4, 1931UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No.2,848,173 August 19, 1958 Friedrich I-Iebberling It is hereby certifiedthat error appears in the printed specification of th e above numberedpatent requiring correction and that the said Letters Patent should readas corrected below.

Column 4, line '73, for "bracket" read brackets column 8, line 34, forshaft 133" read shaft 113 column 9,, line 13, for

"spindle 116" read spindle 166 line 40, for 'component" read Signed andsealed this 28th day of October 1958.,

(SEAL) Attest:

KARL Ho AXLINE ROBERT C. WATSON Attesting Oificer Commissioner ofPatents

